Mr Williamson had served as Tory chief whip since Theresa May became Prime Minister in July last year.

He had previously served as David Cameron's parliamentary private secretary for three years, having been elected as MP for South Staffordshire at the 2010 general election.

He has been replaced as Chief Whip by Julian Smith, another 2010 intake MP who has served as deputy chief whip since after June's general election.

Mr Smith has been replaced by Esther McVey, who served as Employment minister in the coalition government before losing her seat at the 2015 general election.

She returned to Parliament at the snap election earlier this year after being selected to represent George Osborne's former seat of Tatton.

'THE DAM HAS BROKEN'

Today's mini-reshuffle came as the Scottish Conservative leader Ruth Davidson warned the “dam has broken” and it is time to clean up politics in the wake of the Westminster sex abuse scandal.

Speaking after the shock resignation of the Defence Secretary, the Scottish Conservatives leader said the “boys’ locker room culture” in politics had to stop.

As he quit his Cabinet post last night Mr Fallon told the Prime Minister his conduct had “fallen below the high standards that we require of the Armed Forces”.

Later he told the BBC: “The culture has changed over the years, what might have been acceptable 15, 10 years ago is clearly not acceptable now.

"Parliament now has to look at itself and the Prime Minister has made very clear that conduct needs to be improved and we need to protect the staff of Westminster against any particular allegations of harassment."

Asked if he thought he should apologise, the Tory veteran said: "I think we've all got to look back now at the past, there are always things you regret, you would have done differently."

One ally said: “Alcohol is a power drug which turns some into a Jekyll and Hyde,” while another added: “Has there been flirtation that has been inappropriate? Yes, he will concede that.”

In her letter to the Sevenoaks MP, the Prime Minister paid tribute to his "long and impressive ministerial career.”

Questions still remain about the past conduct of ministers Damian Green and Mark Garnier – both of whom are being investigated by the Cabinet office for claims of inappropriate behaviour.

Contributions from readers

graham669

11:03 on 2nd November 2017

As a chief Whip he will be aware of most of the dirt stored in the whips office! But does he have a clue about defence and the armed forces?
He does have the national anthem tattooed on his backside, a pet tarantula, and a cbe from his ex-boss who wrecked the referendum.
His one redeeming action was to vote remain, but would he do so now? I suspect he would do whatever the PM tells him to, as he did with cameron.
Yet another tory lapdog for the PM.